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United States Patent | 5,513,251 |
Rochkind ,   et al. | April 30, 1996 |
The disruption on the data channel caused by use of the conventional call waiting feature with simultaneous voice/data (SVD) modems, when the data channel is active, is overcome by employing SVD modems in the public switched telephone network and supplying the call waiting signal over only one of the channels made available by such an SVD modem. In an exemplary embodiment of the invention, the call waiting signal from the public switched telephone network is supplied by coupling it into the network side of the SVD modems that are provisioned in the public switched telephone network for providing simultaneous voice and data service. Advantageously, a data call that is in progress will not be disturbed by the coupling of an audible signal into the voice channel. Also, since the connection between the user's local SVD modem and the SVD modem in the network to which he is connected can be maintained while changing the source of the data that is coupled to the SVD modem on the network side, it is possible to implement a "data call waiting" feature as well. Moreover, the fact that a voice call is waiting may be signaled over the voice channel or the data channel and, likewise, the fact that a data call is waiting may be signaled over the voice channel or the data channel.
Inventors: | Rochkind; Mark M. (Greenwich, CT); Strahs; Lee B. (Oceanport, NJ) |
Assignee: | AT&T Corp. (Murray Hill, NJ) |
Appl. No.: | 176003 |
Filed: | December 30, 1993 |
Current U.S. Class: | 379/93.35; 379/215.01 |
Intern'l Class: | H04M 011/00; H04M 003/42 |
Field of Search: | 379/93,94,96,97,98,201,207,215 370/76,58.1,110.1,60,60.1,62,110.4 375/222 |
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